How can I calculate the time differences in 24 hour if the user input is 2255 and 2305 the output should be 10 minutes. I got an idea is to separate the input to 2 parts, 2 digi
String time1 = "2255";
String time2 = "2305";
SimpleDateFormat format = new SimpleDateFormat("HHmm");
Date date1 = format.parse(time1);
Date date2 = format.parse(time2);
long difference = date2.getTime() - date1.getTime();
difference is in millis you can convert it to any unit or you can use DurationFormatUtils from apache-commons to pretty format it.
System.out.println("Duration: "+DurationFormatUtils.formatDuration(difference, "HH:mm"));
apache commons has really nice utility functions, apache-commons (lang)